German Patent No. 32 40 294 describes a device for adjusting the height of a head restraint on a motor-vehicle seat. Arranged on the head restraint is a measuring device interacting with a switching device which drives the adjusting drive of the head restraint. This measuring device, formed, for example, as an infrared-reflecting light barrier, detects the height of the seat occupant at a specific location on the body. The support position of the head restraint is accommodated to the seat occupant as a function of the ascertained height. However, an additional measuring device is necessary for this purpose.
An object of the present invention is to reduce the expenditure for the automatic height adjustment of a head restraint.